JPS6055794B2 - Control rod vibration isolator - Google Patents
Control rod vibration isolatorInfo
- Publication number
- JPS6055794B2 JPS6055794B2 JP53052938A JP5293878A JPS6055794B2 JP S6055794 B2 JPS6055794 B2 JP S6055794B2 JP 53052938 A JP53052938 A JP 53052938A JP 5293878 A JP5293878 A JP 5293878A JP S6055794 B2 JPS6055794 B2 JP S6055794B2
- Authority
- JP
- Japan
- Prior art keywords
- control rod
- control
- guide tube
- vibration isolator
- coolant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Structure Of Emergency Protection For Nuclear Reactors (AREA)
- Monitoring And Testing Of Nuclear Reactors (AREA)
Description
【発明の詳細な説明】
本発明は、高速増殖炉等の原子炉において、制御棒が冷
却材により振動するのを防ぐ制御棒の防振装置に関する
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration isolating device for control rods in a nuclear reactor such as a fast breeder reactor, which prevents control rods from vibrating due to coolant.
一般に、高速増殖炉等の原子炉の出力制御は、例えばボ
ロンカーバイト、ユーロピウムオキサイド等の中性子吸
収物質を主構成要素とする制御棒を炉心に出入れし、原
子炉内の中性子を制御することにより行なわれているが
、このような出力制御の従来の構成を第１図により説明
する。In general, power control of nuclear reactors such as fast breeder reactors involves controlling neutrons within the reactor by moving control rods whose main components are neutron absorbing substances such as boron carbide and europium oxide into and out of the reactor core. The conventional configuration of such output control will be explained with reference to FIG.
第１図において、原子炉炉心１内には、内部中空の円筒
形状をした制御棒案内管２が設けられており、この制御
棒案内管２内には、その上方から断面円形をした棒状の
制御棒３が上下動自在に挿入されている。In FIG. 1, a hollow cylindrical control rod guide tube 2 is provided in a nuclear reactor core 1, and a rod-shaped rod having a circular cross section is inserted into the control rod guide tube 2 from above. A control rod 3 is inserted so as to be movable up and down.
この制御棒３の外径は制御棒案内管２の内径より小さく
形成されており、また、制御棒案内管２と制御棒３との
間に冷却材を流通せしめる冷却パイプ４が案内管２の下
部に接続されている。このような構成において、原子炉
の出力を制御するには、制御棒３を制御棒案内管２内に
出入れするが、このとき制御棒３は中性子およびγ線を
吸収して発熱する。The outer diameter of the control rod 3 is smaller than the inner diameter of the control rod guide tube 2, and a cooling pipe 4 that allows coolant to flow between the control rod guide tube 2 and the control rod 3 is provided in the guide tube 2. Connected to the bottom. In such a configuration, in order to control the output of the nuclear reactor, the control rods 3 are moved in and out of the control rod guide tube 2, but at this time, the control rods 3 absorb neutrons and gamma rays and generate heat.
そして、この制御棒３に生じた熱は冷却材により冷却さ
れる。ところで、前記制御棒案内管２および制御棒３の
断面の形状はそれぞれ円形であり、両者間を流れる冷却
材は制御棒３の軸線方向とほぼ平行に流れることになる
。The heat generated in the control rod 3 is cooled down by a coolant. By the way, the cross-sectional shapes of the control rod guide tube 2 and the control rod 3 are circular, and the coolant flowing between them flows substantially parallel to the axial direction of the control rod 3.
すると、冷却材の流れによる力や組立上の誤差等によつ
て制御棒案内管２の中心と制御棒３の中心とがずれ、第
２図に示すように、制御棒案内管２の内周と制御棒３の
外周との間隙が不均一になるが、このとき間隙の狭い側
は間隙の広い側に較べて出口損失が大きく、流速が遅く
なるため、ベルヌイの定理により圧力が高くなる。した
がつて、間隙の狭い側から広い側に向つて圧力差による
力Ｆが働き、この力Ｆか振動の復元力となつて制御棒３
の振動が発生する。なお、前記制御棒３は図示しない制
御棒駆動機構によつて上部から駆動されるが、この制御
棒駆動機構による支配力は流体による起振力より弱いた
め、冷却材の圧力差による振動は避けられないものとな
る。前述したように、制御棒３に振動が生すると、）第
１図の上部に示すように中性子束の密度分布は炉心の場
所によつて不均一となり、制御棒３の揺動により中性子
吸収量に変化が生じ、中性子束の密度が変動し、これに
伴ない原子炉の出力も変動する。５ このような振動を
防止するため、従来から制御棒案内管２と制御棒３との
間にガイドローラやばねを介装している。Then, the center of the control rod guide tube 2 and the center of the control rod 3 become misaligned due to the force caused by the flow of the coolant or errors in assembly, and as shown in FIG. The gap between the control rod 3 and the outer periphery of the control rod 3 becomes uneven, but at this time, the exit loss is greater on the narrower side of the gap than on the wider side, and the flow velocity is slower, so the pressure increases due to Bernoulli's theorem. Therefore, a force F due to the pressure difference acts from the narrow side of the gap to the wide side, and this force F becomes the restoring force of the vibration and acts on the control rod 3.
vibration occurs. Note that the control rod 3 is driven from above by a control rod drive mechanism (not shown), but since the controlling force of this control rod drive mechanism is weaker than the excitation force caused by the fluid, vibration due to the pressure difference of the coolant is avoided. It becomes something you cannot do. As mentioned above, when vibrations occur in the control rods 3, the density distribution of neutron flux becomes non-uniform depending on the location of the reactor core, as shown in the upper part of Figure 1. changes occur, the density of the neutron flux fluctuates, and the output of the reactor also fluctuates accordingly. 5. In order to prevent such vibrations, a guide roller or a spring has conventionally been interposed between the control rod guide tube 2 and the control rod 3.
しかしながら、原子炉を緊急停止させるためには急速に
制御棒３を挿入しなければならず、この制御棒３の急速
挿入を確保するために、前記ガイドローラやばねにはあ
る程度のあそびが設けられているので、防振効果は必ず
しも充分でない。また、このため、制御棒３の急速挿入
にも問題がある。本発明は、前述した従来のものにおけ
る欠点を除去し、制御棒の振動を確実に防止できるよう
にした制御棒の防振装置を提供することを目的としてな
されたもので、冷却材を制御棒の周囲に旋回させ、この
冷却材の旋回運動により制御棒を制御棒案内管の内壁に
押付けるようにしたものである。However, in order to make an emergency shutdown of a nuclear reactor, the control rods 3 must be inserted rapidly, and in order to ensure rapid insertion of the control rods 3, a certain amount of play is provided in the guide rollers and springs. Therefore, the anti-vibration effect is not necessarily sufficient. Moreover, for this reason, there is also a problem in rapid insertion of the control rod 3. The present invention has been made for the purpose of eliminating the drawbacks of the conventional devices described above and providing a vibration isolating device for control rods that can reliably prevent vibrations of control rods. The control rod is pressed against the inner wall of the control rod guide tube by the swirling movement of the coolant.
以下、本発明を図面に示す実施例により説明する。The present invention will be explained below with reference to embodiments shown in the drawings.
なお、前述した従来のものと同一の構成については、図
面中に同一の符号を付し、その説明は省略する。第３図
は本発明の第１実施例を示すものであり、制御棒３の外
周には、螺線状の流体ガイド５が形成されており、この
流体ガイド５の軸線は制御棒３の軸線と一致している。Note that the same components as those of the conventional device described above are denoted by the same reference numerals in the drawings, and the explanation thereof will be omitted. FIG. 3 shows a first embodiment of the present invention, in which a spiral fluid guide 5 is formed on the outer periphery of a control rod 3, and the axis of this fluid guide 5 is aligned with the axis of the control rod 3. is consistent with
そして、この流体ガイド５の外径は制御棒案内管２の内
径より小径とされており、制御棒３の進退時に流体ガイ
ド５が制御棒３の移動の妨げとならないようにされてい
る。このような構成によれば、冷却バイブ４から冷；却
材を流通させると、冷却材は螺線状の流体ガイド５に沿
つて旋回しながら上昇する。The outer diameter of the fluid guide 5 is smaller than the inner diameter of the control rod guide tube 2, so that the fluid guide 5 does not interfere with the movement of the control rod 3 when the control rod 3 moves back and forth. According to such a configuration, when the cooling material is caused to flow from the cooling vibe 4, the cooling material rises while swirling along the spiral fluid guide 5.
このとき、制御棒３の中心と制御棒案内管２の中心がず
れると、第４図に示すように、制御棒３と制御棒案内管
２との間隙が不均一になり、間隙の狭い側ではｊ冷却材
の流速は早く、また、間隙の広い側では流速は遅くなる
。これにより、間隙の狭い側の圧力は低く、また、広い
側の圧力は高くなり、この圧力差による力Ｆは常に間隙
の広い側から狭い側に作用し、流体ガイド５が制御棒案
内管２の内周に当接するまで移動する。そして、最終的
には制御棒３は流体ガイド５を介して制御棒案内管２に
押付けられた状態で停止し、振動は生じない。第５図は
本発明の第２実施例を示すものてあり、前述した実施例
において制御棒３の外周に流体ガイド５を設けたのに代
えて、制御棒案内管２・の内周に流体ガイド６を設けた
ものである。このようにしても、前述した第１実施例と
同様の作用をなすことができる。なお、前述した流体ガ
イド５，６は１条のみに限定されるものではなく、複数
条を組合せてもよい。At this time, if the center of the control rod 3 and the center of the control rod guide tube 2 shift, the gap between the control rod 3 and the control rod guide tube 2 becomes uneven, as shown in FIG. In J, the flow velocity of the coolant is fast, and the flow velocity is slow on the wide side of the gap. As a result, the pressure on the narrow side of the gap is low and the pressure on the wide side is high, and the force F due to this pressure difference always acts from the wide side to the narrow side of the gap, causing the fluid guide 5 to move until it touches the inner circumference of the Finally, the control rod 3 stops being pressed against the control rod guide tube 2 via the fluid guide 5, and no vibration occurs. FIG. 5 shows a second embodiment of the present invention, in which instead of the fluid guide 5 provided on the outer periphery of the control rod 3 in the previously described embodiment, a fluid is provided on the inner periphery of the control rod guide tube 2. A guide 6 is provided. Even in this case, the same effect as in the first embodiment described above can be achieved. Note that the fluid guides 5 and 6 described above are not limited to only one thread, but may be a combination of multiple threads.
本発明に係る制御棒の防振装置は、前述したように構成
したので、制御棒の振動を防止し、制御棒の振動による
原子炉の出力変動を防いで極めて安全性の高い運転をす
ることができる。Since the control rod vibration isolating device according to the present invention is configured as described above, it is possible to prevent vibration of the control rods, prevent output fluctuations of the reactor due to vibrations of the control rods, and perform extremely safe operation. Can be done.
また、制御棒と制御棒案内管との間隙を充分な幅に保て
るので、原子炉の緊急停止のための制御棒の高速挿入も
確実に行なうことができる。Furthermore, since the gap between the control rod and the control rod guide tube can be maintained at a sufficient width, the control rod can be inserted at high speed for emergency shutdown of the reactor.
第１図は従来技術の構成および制御棒の位置による中性
子束分布状態を示す説明図、第２図は第１図の■−■線
による断面図、第３図は本発明の第１実施例を示す説明
図、第４図は第３図の横断面図、第５図は本発明の第２
実施例を示す説明図である。
１・・・・・・炉心、２・・・・・・制御棒案内管、３
・・・・・・制御棒、４・・・・・・冷却バイブ、５，
６・・・・・・流体ガイド。Fig. 1 is an explanatory diagram showing the configuration of the prior art and the neutron flux distribution state depending on the position of the control rod, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a first embodiment of the present invention. 4 is a cross-sectional view of FIG. 3, and FIG. 5 is a cross-sectional view of the second embodiment of the present invention.
It is an explanatory view showing an example. 1...Reactor core, 2...Control rod guide tube, 3
...Control rod, 4...Cooling vibe, 5,
6...Fluid guide.
Claims (1)
設け、冷却材の旋回運動を生じさせて制御棒の振動を押
えるようにした制御棒の防振装置。1. A control rod vibration isolator in which a spiral fluid guide is provided in the gap between the control rod and the control rod guide tube to generate swirling motion of the coolant to suppress vibration of the control rod.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP53052938A JPS6055794B2 (en) | 1978-05-02 | 1978-05-02 | Control rod vibration isolator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP53052938A JPS6055794B2 (en) | 1978-05-02 | 1978-05-02 | Control rod vibration isolator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54144588A JPS54144588A (en) | 1979-11-10 |
| JPS6055794B2 true JPS6055794B2 (en) | 1985-12-06 |
Family
ID=12928801
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP53052938A Expired JPS6055794B2 (en) | 1978-05-02 | 1978-05-02 | Control rod vibration isolator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6055794B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5237595A (en) * | 1990-02-26 | 1993-08-17 | Westinghouse Electric Corp. | Guide plate for guide tubes used in nuclear reactors |
| FR2734943B1 (en) * | 1995-05-30 | 1997-08-22 | Framatome Sa | CONTROL CLUSTER FOR A NUCLEAR REACTOR |
-
1978
- 1978-05-02 JP JP53052938A patent/JPS6055794B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54144588A (en) | 1979-11-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7773716B2 (en) | Fast reactor having reflector control system and neutron reflector thereof | |
| EP2889878B1 (en) | Burnable absorber-integrated control rod guide thimble | |
| JPS6055794B2 (en) | Control rod vibration isolator | |
| JP6579842B2 (en) | Fuel element and fuel assembly for fast reactor and core loaded with the same | |
| US4311560A (en) | Stabilizing device for control rod tip | |
| US4332030A (en) | Paired absorber elements for gas cooled high temperature reactors | |
| JPH0134358B2 (en) | ||
| JP3056803B2 (en) | Reactor control rod | |
| JP2015059791A (en) | Fast reactor core and fast reactor comprising the core | |
| US4274920A (en) | Water-cooled nuclear reactor with passive emergency shutdown and core cooling capability and on-line refueling | |
| JP2020180907A (en) | Fuel element, fuel assembly, and core | |
| JPS586920B2 (en) | control rod assembly | |
| JPS598797B2 (en) | nuclear fuel assembly | |
| JPS62212592A (en) | Control rod | |
| JPS63298191A (en) | Fuel rod | |
| US3677891A (en) | Antijam sliding seal structure | |
| JPS62191793A (en) | Control rod | |
| JPH0785114B2 (en) | Control rod | |
| JPH07270568A (en) | Double layer pellet of nuclear fuel | |
| JPS6046487A (en) | Control rod for nuclear reactor | |
| JPH0352598B2 (en) | ||
| JPS5927289A (en) | Control rod assembly | |
| JPS6375693A (en) | Control rod buffer | |
| JPS6156991A (en) | Control rod aggregate | |
| JPH063478A (en) | Fuel assembly and core of reactor |